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Discussion Starter · #1 ·
Okay guys, apologies I have been MIA for gaps at a time but I've been busy working on well.... everything.
Life, my job and of course the truck.
I have two sets of jobs to post up and I'll start with the Revo Gear install I started but am yet to finish.

It all started after I took my truck out last year for the first time and I really noticed I needed to put the gears in.
I wasn't as low as I wanted to be offroad and churning those 37" meats I need more torque!

Around Christmas, the throwout bearing went on my New clutch. Yes New!
Either the piece was crap or the mechanics didn't seat it all the way in, when I put in the Ar5 in my truck last year.
Towed it home and decided this was the opportunity to gear the case. So I dropped off the truck at the same mechanic shop and when they had the trans and case off and apart,
I picked up the case and started nightly working on it, hoping to get it geared down with those lovely Inde4x gears I been holding on to.

Big Thanks to Jerry @JLEMOND and Brad @bradzuzu for all the help with the little things and Kurt in Spartanburg, SC (not on the planet but the Isuzu force is strong with this one)

I didn't get it swapped out in time and had to pick up a junkyard Tcase so I could get my truck out of their shop.
But not a big deal. Now I have a spare. :D

So here goes and hope this helps you guys.
These are the parts you get plus a few quarts of gear oil from Matt at Inde4x.
Whats missing in this shot is the shift rail that is cut a little to clear the big gear.


Here is a close up of the front output and shift business on the Case. Keep in mind this for an Auto Case. Just so happens to bolt up to the Ar5.

Important here, Take the bolts off the shifter and get a telescoping magnet to pull the balls out from the detents.
I'll post a pic later when I can find it.
Remove the magnetic pickup sensor from the side (the one with the wires)

I loosened and removed all the bolts and start to pry at the case.

This is an upside down view of how the inside of the case looks apart.

Your first step is to remove the bearing on the main shaft. I can't remember if there is a snap ring in place or not but that is an easy thing to remove.

Now the hard part, I put a flat head screw driver in place on the inner clutch gear to hold it still and hammer-tapped the socket to break the big nut free.
This took some time and patience. It will suck. I promise. If you have the case still in your truck you could leave the front shaft hooked up and the nut would come right off, because the driveshaft will keep it from turning.
I am not holding the flat head screw driver on any of the teeth. If you look at some of the other pictures, there are three slots to hold on the inside.
 

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Discussion Starter · #2 ·
Once you have that big nut off, now its time to get the snap rings loose so you can pull the gears out.
There is a trick to this I learned from Jerry and Curt. Wrap a zip tie around the 'ears' and pull tight, that way you can hold the snap ring 'loose' and it will come right out.
I promise.

Now here is where I got lost.
Do NOT do this:

I repeat do NOT do this above.
So here I am every night on my kitchen table working on this thing.

I used the flat board to put underneath to help keep the Case flat.
I repeat do NOT pull the clutch gear off like this. I stopped for the night and made a few phone calls.
What you need to do is knock out the roll pins in the shift rails.
Big Thanks to Brad because he showed us all how to cut down an Allen key to remove the "L" and I used that. It is stronger than the punches I had, which broke.
SO yeah use his trick!

See below for my punches, one broken and the allen key on the right of it is the winner!


And Bam! like that the clutch gear and shift fork come right off!


here you can see the 4wd shaft and clutch and 3 teeth. Do not lose these!!
You can also see my zip tie in place still.
 

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Discussion Starter · #3 ·
Here is a shot at the counter shaft (or idler shaft its called sometimes) and the main shaft.
They don't clear unless you get a few things free. Do NOT force this. I promise they don't come apart unless you get the shift rails free.

You get the shift rails out, then pull the idler out, then pull the shift fork off.

Keep in mind how the 'paddles' work. If you are not mechanically sound, then take a video of how they work so you know which way they go.
It is important to understand how this works to actuate the gears with the clutches as you shift from 4wd hi to 2hi and then obviously to 4low

And like that, here comes the main shaft set

Boom - empty case:


here is another really 'fun' part. Get your pulley puller and put it around the clutch gear on the main shaft and you may need a helper to hold it still but the first time I got this to move was probably the hardest I have ever tried to turn Anything, ever. So if yours is old just like it should be... plan on a helper here.

You will hear popping as you turn and I promise it will come off, just don't break it, because the clutch gear is RARE as hens teeth. Jerry only has old ones with different tooth counts.
Spray it with breaker spray and tap the break bar as you do this, Take your time.
Do not break this.
Here it is apart:
 

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Discussion Starter · #4 ·
Here are the Gears. The top one is the Revo and the bottom one is stock.
You can see how much of a difference this is.

Put the shaft back in the case and put the near gear on so you can see how everything fits.

I am telling you now that the gears will not go together in 3 separate pieces. Because of the size of the gears, collectively you will have to put them all in at once.
This requires a third hand, the Force or magic.
But the pic below is to show how things go together.

Put the clutch gear back on with a Press or do what I did and hammer it down with a sleeve, evenly I remind you!



On the left here is the stock idler shaft and on the right is the Revo shaft gears. Massive difference and you will see soon why you can't put these together independently.

Pull the bearings off and remember which was what 'out' on each bearing.

On the stock on is a 'quiter' gear. Its a thing plate that according to Kurt and Jerry, you don't need to install with the new set. Isuzu put these on there to quiet the Case down and stop the whining.
It has one less tooth than the stock gear set. I had to take apart the gearset like 5 times before I figured this out.
So yeah you DONT need the plate and the small toothy gear. You do need the roller sleeve though.

Get your bearings back on and snap rings. (disregard the toothy quieter gear and the plate in this pic, I don't have a pic without them yet)

 

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Discussion Starter · #5 ·
You can see in this pic the difference in the main shift rail.
There is a 'slot' cut out of the new one to clear the Huge idler gear.

Plus the roll pin hole is in a slightly different spot.
Test fit the two together to see how I need to get this back together.

The zip tie trick helps a lot here so nothing is permanent just yet.

On the 4wd shaft, you will need to rotate the clutch gear to find the 3 grooves in the brass looking gear set and put the 3 teeth back in.

The little 'humps' face out and here you can see how 'springy' they are. Kinda need a helper for this part to get the clutch gear around it.
It wants to come apart so you have to hold the teeth in place and keep the brass thing from moving on you.


It will stay together if you let gravity keep the gear and clutch set downwards.

Test fitting all this together shows you that you need to install all 3 gears together.
You can't clear the idler gear from the bearing on the 4wd gear. I know it sucks but again I tell you, use magic, or use the Force or a third hand.... you need a helper here.


One thing to notice in this pic below is a slot. You can reach in the shifter hole with a flat head screw drive and (depending on if installing or removing) you can hold down or pry up the snap ring once you have it zip tied together.

I didn't see this until later but the Japanese Isuzu makers were smart in providing little things like this to get stuff apart without being a pain in the taint.

Here is a shot of the 4wd shaft and snap ring placement after you cut the zip tie off.

This shot shows how the snap rings have a 'home' so make sure they are in their grooves.

 

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Discussion Starter · #6 ·
Boom Almost done!

You can put the front flange back on now.
Now move everything and shift it all 'dry' so you can see everything work. If it doesn't work right, then start over.


Put the big nut back on.

I used a 1 and 5/8 socket.

Hammer the pins back in

put the bearing back on the main shaft

There is a snap ring on the bearing to put back on too


This is the back half of the case. THere is an output gear set that touches all kinds of stuff when in 4wd hi and low. So now to put the case clam shells back together.


Now for the bad news. The case didn't close all the way and I couldn't turn the gears at all the closer I got to sealing the unit.
SO I called Jerry and Kurt and they both said to make sure I had the little ball bearing on the main shaft. I took it all apart again and I didn't lose the ball at all.
So yeah it turns out the quieter gear and the plate have to be remove from my job ( like I said above)
At this point, I had to stop and get the junkyard case and give it to the mechanics to get my truck out of their shop. They only have 3 bays, and I was taking up one of them.
So I will get back on this very soon.

Here is a shot of all the shift rails out.
You can pop the covers out with a blunt phillips head so you can see how they line up.
very important when putting back together: The shift rail with the coil spring wrapped around it has a slit in the end. There is a tiny metal rod in the case that this MUST match up to when assembling.
See here:

The upper left hole you can barely make out the tiny rod. And in my palm you can see the 'covers' (caps)

So now to try this all again.

Very helpful pic for everyone here. Note the ball bearing in the main shaft. #10 in pic - This keeps the 'spindle' from rotating independent from the main shaft and keeps everything working the way it should.



Now a few weeks ago I started back on this but the damn clutch gear and shift fork are buggered. They don't slide freely anymore, and I may need to get another junkyard case.
Because Jerry has none available.
These should move freely and I think I slightly bent or warped it using my flat head screw driver to get it off. Dang it!!

Luckily the cases in the yards are like $75 so it shouldn't hurt too bad, plus I get spare parts if I keep Fing up.


Anyhow, I hope to get back on this soon.
I just recently finished off a massive water pump, timing belt, drive belts, valve cover gaskets, intake gaskets, hoses and pipes and new radiator ... job.
I had a bad water leak and decided to tackle the whole damn thing. So the case became a secondary thing.
:D
 

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Great thread and great pictures. This looks like it qualifys as a serious learning experience. Bummer about the shaft bearing, but will undoubtedly help someone else in the future. How did you get away with doing this on the dining room table? My wife would have changed the door locks if I tried... :lol:
 

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Discussion Starter · #8 ·
It wasn't the bearing and the shaft. It was the clutch And gear set that is buggered.
I'll tackle it again here soon.
As for the dining room table, I put everything back on the floor all wrapped up at the end of the night after I was done.
For now, it is just my son and I in this house. So yea, I hear ya!!!
I do have a garage but not a workbench large enough to work on something like this.
I used to in my old house but I don't give a turd about this dining room table. You should see it now. It is full of dents and marks from all the banging around.
 

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I was looking at the 10 marked bearing on the main shaft and thinking how easy it would be to miss. This looks like doing a rear end X 10. Transfer case is not something I need (or want) to do, but if the time comes I think your pictures will be pretty helpful. My take on these big jobs is no matter how many times I break something or screw it up, eventually I'll get it fixed. Looking your thread over I'd start with the bad one I pulled out and at least two spares from the junkyard available. Since I break a lot of crap, I'd probably need a third one too. :lol:

Good luck on getting the clutch and gear set up straight!
 

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I've been wanting to do this my self. Will any 4L30-E transfer case bolt up or does it have to be a 2nd gen rodeo/amigo case?
 

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Discussion Starter · #11 ·
If you want a stick shift transfer case, you will need to get 97 and down.
98+ is push button activated and has a electronic motor you'd have to wire up.
Might be an option for you because isn't the chain driven case behind the 3.5 a push button?

The early 4l30 tcases didn't have sotf but I don't know if you want to go that far back.
 

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lorenzo816 said:
If you want a stick shift transfer case, you will need to get 97 and down.
98+ is push button activated and has a electronic motor you'd have to wire up.
Might be an option for you because isn't the chain driven case behind the 3.5 a push button?

The early 4l30 tcases didn't have sotf but I don't know if you want to go that far back.
by stick shift do you mean having 2wd, 4lo and 4hi on the t-case or just 4lo and 4hi? On the sotf cases it's still a full time 4x4 case, the front axle is just different. Unless maybe you're talking about the TOD troopers? Which mine is not.
 

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Discussion Starter · #13 ·
The SOTF cases are not full time 4x4.
Because I have had well 3 of them now.
When you shift to 4wd with a SOTF case, a signal is sent to the VSV up front to suck air from the intake and move the front axle shift fork over on the driver side.
I mean stick shift case as in 2hi, 4hi and 4lo and it don't matter for me any more about SOTF.
Because I have no IFS or front shift fork.
The earlier cases that weren't SOTF, didn't have a shift fork on the front axle and you'd have to completely stop to go in 4wd.

I was saying about yours being push button, you might could go swap for a newish push button case because it's looking for the electrical signal to operate and the SOTF for the vsv, which in your case could work fine.
Make sense?

Side story here:
Jerry and I were talking and came up with a poor mans locker for the front.

You weld the spider gears up front so that when in 4wd you're actually in 3wd until you actuate the shift fork, and at that point you're 4wd and locked up front.
This is of course if you could wire the shift fork independent of the tCase.
Genius!
 

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what I meant about the sotf cases being full time is that it always deliver power to the front axle. The power just doesnt get delivered to the wheels depending on the forks position. But anyways, those older t-cases will bolt right up? I've always liked the older style where you have to shift into 4wd vs just hitting a button.
 

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Discussion Starter · #15 ·
No they don't. There may be some parasitic movement from the internals but no driving force to the front.
That is the point of the 3 different positions.
 

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lorenzo816 said:
No they don't. There may be some parasitic movement from the internals but no driving force to the front.
That is the point of the 3 different positions.
the sotf cases have 2 positions though. or are you talking about the older standard case?
 

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Discussion Starter · #17 ·
Getting slightly off topic here but...
The old cases that are not SOTF have no shift fork up front on the driver side axle shaft.
I think they run until about 93-94 possibly 95 first half of year since its the break-over year.
The 4wd I have had on the mua5 and the case I have now from the auto 4l30 are SOTF because they have the 4wd sensor on the side (2 wire mag pickup) to send a signal to the Vacuum Switching Valves to change direction and push the Shift Fork over.
Must be a misconception here if you think the 3 position cases were not SOTF.
SOTF has everything to do with the VSV and nothing with being 2 position or 3 position cases.

Now that you have me thinking about it, the 2 position is 2hi or 4lo and the push button activcates the 4wd, correct?
Then you could wire the VSV separate from the case and you would be able to get 2lo (no shift fork engaged, however in Low gear) 2hi (standard positions), 4hi (push button and vsv engaged) and 4lo (push button and vsv engaged and in low gear).
 

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Hey buddy, I found it!!!! :D

This is perfect and maybe the motivation I need to get this under way.

cheers
-Ian :blackeye:
 

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Would you possibly be able to take a shot of the front of the transfer case, where the trans bolts up? I'm trying to figure some stuff out for my drivetrain swap and I need to get a good look at the trans adapter bolt pattern...
 

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Discussion Starter · #20 ·
Since I don't have the 4l30 trans, I don't have the 'adapter' plate to bolt the case to the auto.
The auto t-case bolts right up to the Ar5. (we found this out via Jerry and some other research)
The 4l30 is short a few inches compared to the Ar5 and has an adapter bracket to mount the case to it.
Funny how the 4l30 adapter bracket and bolt on pattern preceeded the Ar5 being used behind the 3.5's however they have the same bolt pattern. And even more astounding that the Ar5 had a chain case!
Wacky but it works out to my benefit. I'd rather have a gear case.

What are you putting this on?

I actually took a shot the other day for a guy in Panama wanting to see if it would mate up to his Diesel engine.
The Mua5H (yes 'H") has an output that is damn near similar to the Ar5 output bolt pattern.
We're still doing some measuring and he is going to test fit from another Isuzu down there.
I'll post that up eventually once we find out more information.
Would be very interesting to find out that they same case can be used on a diesel trans that originally had a DSD case on it.

Now I'm getting off topic but anyhow, here is the pic I took of the female end = the tCase front face that bolts to the trans.

 
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